Growth Stimulating of Fertilizer on Quercus glauca Seedlings and Its Nutritional Mechanism

Four nitrogen concentration gradients(0.1, 0.2, 0.3, 0.4 g/plant) for each fertilizer and 1 control treatment were set respectively. At the end of the growing season, the biomass, nutrient element mass fraction and matrix enzyme activity were measured, the nutrient element accumulation and allocation ratio were calculated, and the effects of different nitrogen application rates of slow-release fertilizer and compound fertilizer on biomass, mass fraction and accumulation of nutrient elements and matrix enzyme activity of Q. glauca container seedlings were analyzed. The findings revealed that the application of slow-release fertilizer and compound fertilizer was conducive to the improvement of nutritional element accumulation and matrix enzyme activity of Q. glauca container seedlings, and the treatment of slow-release fertilizer was almost always better than compound fertilizer under the condition of the same total nitrogen application amount, and the improvement effect of each nutrient index and matrix enzyme activity was the best under H₃ treatment. Under H₃ treatment, the accumulation of total biomass of Q. glauca container seedlings increased by 86.24% compared with CK, the accumulation of nitrogen, phosphorus and potassium elements in the whole plant was 2.85, 2.09 and 2.47 times that of CK, and the activities of urease, catalase and sucrase in matrix enzymes increased by 18, 2.84, and 2.81 times, respectively. In nutrient element distribution, fertilization was more conducive to increasing the aboveground allocation ratio of biomass and nutrient element accumulation of Q. glauca container seedlings. In the correlation analysis, biomass, element accumulation and matrix enzyme activity were positively correlated with each other. In terms of nutritional element accumulation and matrix enzyme activity of Q. glauca container seedlings, the effect of slow-release fertilizer application was generally better than compound fertilizer, and in most cases, the nutritional status and matrix enzyme activity of H₃-treated Q. glauca container seedlings were the best, and it was recommended to apply 2.14 g/plant slow-release fertilizer when cultivating high-quality container seedlings of Q. glauca, and the nitrogen consumption was 0.3 g/plant.